From: Eric Biggers <[email protected]> MACs should, in general, be compared using crypto_memneq() to prevent timing attacks.
Cc: Mimi Zohar <[email protected]> Cc: Herbert Xu <[email protected]> Signed-off-by: Eric Biggers <[email protected]> Signed-off-by: David Howells <[email protected]> --- security/keys/encrypted-keys/encrypted.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 702c80662069..5c98c2fe03f0 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -30,6 +30,7 @@ #include <linux/scatterlist.h> #include <linux/ctype.h> #include <crypto/aes.h> +#include <crypto/algapi.h> #include <crypto/hash.h> #include <crypto/sha.h> #include <crypto/skcipher.h> @@ -534,8 +535,8 @@ static int datablob_hmac_verify(struct encrypted_key_payload *epayload, ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len); if (ret < 0) goto out; - ret = memcmp(digest, epayload->format + epayload->datablob_len, - sizeof digest); + ret = crypto_memneq(digest, epayload->format + epayload->datablob_len, + sizeof(digest)); if (ret) { ret = -EINVAL; dump_hmac("datablob",
